Hi again,
can you elaborate on 'stops working' ... does it become limp, forceless, or does it just hold in a specific position, does it still react to gyro inputs (hold but no stick control), whatever?
If replicable on the ground, you could remove the tail belt, only have the mechanics running without tail, to check if it's static or maybe something elseāno belt, no ESD.
I am sorry for the inconvenience, but to fix it we have to know where to look, first.
Kind regards
Eddi
Born to fly ...
forced to work.